Telephone apparatus.



7 B. D.; WILLIS. 'TELEPHONE APPARATUS.

' APPLICATION FILED OCT. 5,1906- Patented Mar, 14, 1916.

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illmhlllllr wmv @my HUA@ mvo @Q TELEPHONE APPARATUS. APPLICATION FILEDocT. 5, 1996.

1,175,896. Patented Mar.14,1916.

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Q llllllllllllHhIA UNITED sTATEs PATENT CEEICE.

BERNARD D. WILLIS, or' CHICAGO, ILLINOIS, AsSIGNoR, BY MESNEASSIGNMENTS, To

FIRST TRUST AND SAVINGS BANK, TRUSTEE, or CHICAGO, ILLINOIS.

TELEPHONE APARATUS.

Specification of Letters Yatent.

` A.Application pled October 5, 1906. 'i Serial No. 337,593.

l'o all tv/wm it may concern Be it known that I, BERNARD D. WILLIS, acitizen of the-United States of America, and resident of Chicago, Cookcounty,Illinois,

- .5 have invented a certain new and useful Im- A Special objects ofmyinvention are the provisionof improved means for enabling' j a callingsubscriber of an automatic ory semiautomatictelephone exchange to attact the attention of and secure telephonie communication with a centralstation operator or attendant; the provision of means whereby, out o f aplurality of lines each provided with oneor more telelhones, line may beautomatica y selected by a Call ing subscriber whose telephone receivestalkf ing current from a common battery at lthe exchange or centralstation; and the provi sion of certain details and features-ofimprovement. and' co-mblnations tending to increase the generaleliiciency and improve the service ot' a telephone exchange system.

'lo the foregoing and `other useful ends,

my invention consists in matters hereinafter set forth andclaimed.

A40 In the accompanying drawings, Figure 1 is a ydiagram showingasubscribers automaticsubstation at A, a central battery at B having itspositive terminal preferably `grounded pat G. C indicates the well-knownchange. At Dis shown the relay and circuit connections ot'my improvedsignal-re#- eeiving apparatus. The substation A has operated thefirst-selector C, which latter in ,50 turn has selected a line of whichDis a the first idle` line extended 'from the first operators posi .tionto the second, ope 'ators Vposition by throwing the key F. The attendantat the second position, in like manner, and by throwing the key H, mayin turn extend the trunkline to the thirdv position; thus when the trunkline-is seized the signal will be transterred to position #3 withoutsignaling posi-tions #l and #2.

For convenience ot' explanation, assume that in an automatic exchangethe naughtlevel of ten contacts is connected withtrunk lines leading toa tollboard, and that the tollboard terminal of each of said trunk linesis provided with one of my improved signaling arrangements. Theoperation of the signaling equipment, as used in this connecvPatentedMar. 14,1916.4

tion, is illustrative of its action in any connection in which it may beused.

The substation A maybe of any suitable or approved type. The substationA comprises a receiver 2, switch-hook 3, inductioncoil 4 which consistsof the primary winding and secondary winding 6, transmitter 7, condenser8, ringer 9, impulse wheel 10 which has the usual vertical impulse teethl1 rthat-are adapted lto operate the vertical impulse spring 12. Theimpulse wheel carries the rotary ilnpulse tooth 13, which latteroperates the rotary impulse spring 14. The

'switch-hook has radiating trom its body a 'number ot cam-arms 15, 16and 17, and is sov y pivotally secured to the key board (not M shown) bythe screw' 18 about lwhich it moves.

when the receiver is removed. The movement is produced by a spring andV,the switch-.hook is pushed -up for the purpose ot' changingcertaincircuit connections to ,be disclosed. The cam-arm 15 controls theso-called locking arml9. After the dial is rotated the locking arm.19occu pies the position shown at substation A. The mechanical operationsby which thisis brought about are well known. The coperating groundsprings 20 and 21 engage, thus placing the ground post 22 in Contactwith the substatlon Iground G1, whereby when the subscriber releases thedialy for ro,- tating it, as described, the vertical impulse teeth y11Awill Cause the Y' vertical impulse spring 12 to come in Contact with theground post 22, and immediately following the rotary `impulse tooth 13causes the'rotary impulse spring 14 to come in Contact witlrthe sameground post 22. .When the switch-hook (not shown) vbridging Athe gseparation ofthe springsand Y 10- `may signal another subscriber Lnection ,has been established comprises a anda spring 29, which lat` Vthe"switclrho t, ductors simultaneously.

beofany suitable stance ofthe generalv type described in'Patl issuedMai-'ch 131'906toy,r and" Erickson.l .It eiiibod f details the following'ivell- .l i knowndevices and circuits: A-switch-shaft-,g-'(no'tshown)-V carriesthevertical and rotaryf" Keith,v Erickson i 'llaye@ and i vhile the Vsideswitych is infir'st magnet 48, which f cally.I Bv moans of the l 'shaftaiid.shaft wipers ciilaiidircction"scriher.controls the i'clea y' V the side "sw positioin then, sincecontrolled through the "which ,la connection has y j"'"isdown the.cam-arin 17 maintains a' con--v :tactibetween the springs 23 and-24,.ther eby denser 8 in .series with' the' u ringer acrossthe line.The springs .-2 5y and .26` are then disengaged, and the 'primarycircuit including the windinginl lseries with; the transmitter 7 isinterruptedl 26;y y a subscriber 1 yThe signalingdevice whereby [Pushvbutton ter@ normally engages the con-tach-point :3.0; fbutv when thepush button 2 @pressed the d spring 29 leaves the 'Contact pint 30am]whichlatter engages the, contact point 31, I gis :onnectedlvii-*ith thesubstation ground G1, Theinveaiis whereby *the subscriber may re.-`

lease;- theentral station apparatus lbrought, '245`-intofgservice,comprises three springs 32, 33

.` asdfl known .as the release-springs aiidso` controlled-hvthejcani-arin 1G rthat when;l

ok descendsthe' three release#y springs are brought intol contact,thereby. goui'idin both the subscriberslinecon;l `Thefirst-selectorswitchshown at O may.4

`or approved type, for'in `eagle@v 815,321,

wiesglamong other D wipers m89 -and 40,`

respectively,4 and the private iviperzll.`

wiper, respectively. c The side switch isunlil 'dergthe control 'oftheprivate magnete@ Through tht-ii'i'ed'iuin Aof' the vertical linereposition;Y the shaft and shaft wipers 395 40 and 41 verti-L`position,1thc .subscriber `controls thepi'ivate itch., is' in secondvposition `the rotary magnet 50, which fcarriesr the in' a rota-ry 'oi'cirf:

l ino relays .V47 and Jgf'actinglconitch is -iii` first sible.

'throughfthe windin f The side switch is well f' line receiveswcurrentroinfthe grounded f known and comprises' the side sv\ 'itch`wipei's'l-which inaybe designatedv`l` as verticahlrotary: and' private sideswitch `Wipersi'andf'therotary.magnet side 'switch-A IOtll'y line relay4993iA is ciiergized. Thevertical relays arid battery B. This isdesirable,

because if the relays are the battery, ing the subsc'rilier'm selectorAswitch. C ott" fn0r1n'al.` I

j siralfile to remove thelbridg'e'forined through It is'-also de-A Thdebridge# not disconnected i'roin each other, and troni the ringingcurrent for signalay operate veither or f y, both yof theipifelays'-li'V and 49; iiiovingthe after a; con-i f the voice-curne s as`clearl--a path as poshe/ first-selector switch-shaft is also with anormal post arm which,

"provide V whenthe shaft is in nornialaposition,'closes rso the springin Contact withV thed contara?- yIpoint` 56; but ywhen the shatt israised one vorniore Stepsthespring 55 closesincontact f with thec'ont'actpoiiity 575 'by which switching 'means' the switch' is Bladeybusy-while ,off normal, and ther eiiergiz ferential relay ($3 thecalling substationv lis' ing" circuitiffor' the relay 53 iscontrolled.

My improved apparatus:comprises averf* tical relay r58,r a rotaryi`vrelay 59 havingtwo- ,-"windi-ngs 60` and Giri-eleasiii'g relay@ which,releases the rotaryielay') whentlie latter ,'pi-'oifided'with` talkingbattery current when the operatos -keyl E 1s throwntoilisteningposition.' The rotaryrl'lin'e receivescuri-entf* froinjthe non-grounded'pole of the batteryg 64, and the.'` vertical through the. winding G5relay 68; The lamp reif *iny Fig. lthe springs'68`and69, and 'Wand 'i 7lare pressed rinto Contact, "thus bridging j the operators receiverseh-across the trunk subscriber controlshthe vertical-v` latter operates.to raise the line' by way of the condensers? and 73.1 The operation o.thewspring 'V75A i spring 76, andthe lspringsv 77qand. 78 to dis`enriage'."-y

ier

terseparates the springs 23 an i-eii'ioviiig the ringerfroin'across theline and. `substituting thereforuthe primary' circuit vbyperii'iitti'iigfthe sprii-ifgs 25 and ftofclose. Sinoethe trunk lineslead off from the @naught-level of the `frs't-sehectOrS, the sub-.scriber" suitably` operates "his dial' for the l digit O, therebygrounding c'indu'ctor 79 -ten timesgf-aiid vthe rotary linev conductor80 `once upon the return motion of the dial. ;The, ground l 0st 22 is'placed iny connection with the s station ground G1' 1'10 fthe key 'falso,causes the Aspring-17l to' pass v'fronti engagement `with ntoengagementwith the" A removes the lrethe vertical line relay eXtends from `theprivate magnet 46 times energizes the vertical line relay 47 of thefirstselector. The circuit through said ground G1 through the springs 20and 21, vertical impulse spring 12., vertical line conductor 79,sideswitch wiper 42, Contact point 81, through the winding of thevertical line relay 47 bridge-cutoff springs 82 and 83 to the batterylead 84, thence thro-ugh battery B to ground G.. Each time the verticalline relay 47 is energized the springs 85 and 86 are pressed intoengagement an an energizing circuit is established each time through thevertical magnet l48. The circuit through the said magnet extends., from:ground IIGL to the springs 85 and 86, to the private magnet springs 87and 88, yertical magnet 48 to the battery lead 84, thence throughbattery B to ground G. The vertical magnet being operated ten times thefirst-selector switchshaft and wipers 39, 40 and 41 are carried to alevel with thecontact points that constitute the terminals of the trunkline leading to thecircuit D. Following the vertical impulses the rotaryimpulse spring comes incontact with the ground post 22, therebygrounding the rotary line conductor 80 once and energiz'ing'the rotaryline relay 49 of the first-selector once. The path of the energizingcurrent may be traced as follows: from `the substation ground Gr1 to therotary line conductor 80, side ,switch wiper 43, contact point 89 to therotary line relay 49, bridgecut-oi` springs 90, 82 and 83 to the batterylead 84, thence through battery B to ground G. Therotary line relay49upon energizing closes in contact the springs 91 and 85, therebyclosing an energizing circuit through which extends from ground G2 tothe springs 85 and 91, private magnet 46 to the battery-'lead 84, thencelished throu through battery B to ground G. The private magnet 46beingenergized for a` moment the side switch of the. first-selector C passesfrom irst'to second-position, thereby permittingthe side switch wiper 45to engage the contact point 92, thus closing a circuit! through therotary magnet 50. The current flow is from the groundG3 to the contactpoint 92, side switch wiper 45, interrupter springs 93 and 94, throughthe winding of the coil of the rotary magnet 50, thence to the batterylead 84, and through battery B to ground G. The rotary magnet isenergized one step `and the shaft wipers 39, .40 and'41 are carried intoengagement with the bank contacts'that constitute the terminals 4of atrunk line leading to the circuit D.

Assume that the trunk leading to the said `circuit/leads oi' from therst set of con- J`tacts of the` naughtdevel.

l If the first trunk an energizing circuit is estab'- Ah theprivatemagnet 46 when line is busy the private wiper 4-1 strikes the busyprivate bank contact, which is, of course, grounded,

thereby retaining the side switch in second position and maintaining theenergizing ciri cuit through the rotary magnet 50. The rotary magnet byintermittent magnetization thus causes the-shaft to rotate step-by-stepand carry the wipers past the last busy trunk line. vHowever, as soon asthe rivate magnet is denergized the side switch is tripped into thirdposition; but if there are no busy contacts to be passed over, asassumed in the first instance, `net 50, as is well known, trips the sideswitch to third position, with the result that the side switch wipers42, 43, 44 and 45 en-` gage their respective contact points 95, 96, 97and 98, thus extending the subscribers line conductors l7 9 andcircuitD. Also, since the side switch wiper 44 engages the ground contact point97, a guarding potential is established at the private wiper 41 forprotecting the seized line from being molested by any other switch.

`When the side switch wiper 44 passes to the ground contact point 97 anenergizing circuit is established through the lamp relay 66. VSaidcircuit extends from ground G4 to contact point 97, side' switch wiper44, release relay 52, switch-shaft private wiper' 41, contact point 99,relay armature'lOO, through the winding of the lamp relay 66, contactpoint 101, relay armature' 102, battery lead 84, thence .through batteryB to ground G. The lamp relay 66 upon energization closes a circuitthrough the signal lamp 67. This cir cuit extends from ground G5 to thesprings 78 and 77, rel-ay armature 103, contact point 104, signal lamp67 to the battery lead 84, thence through battery B to ground G.

he operator in response to the signal throws the key E to the positionshown in Fig. L This results in breaking, at the springs 77 and 78, thecircuit through the signal lamp, and placing in contact the springs 68and 69 and 70 and 71, which bridges the operators set across the saidline, and furthermore the spring 74 disengages from the spring 75 andcomesin con tact with the spring 7 6.i This latter contact closes acircuit which supplies the calling 'substation with current for talkingpurposes. The circuit extends lfrom ground GG the rotary magthrough thewinding 65 of the differential V relay 63, contact point 105, relay'armature 106,'springs 76 and 74, through the winding of the Verticalline relay 58, conductor 115, wiper 39, side switchwiper 42, verticalline conductor 79, springs 25 and, 26,-push button spring 29, contactpoint 30, transmitter 7, primary winding-5, rotary line conductor 80,side switch wiper 43, contact point 96, shaft wiper 40, conductor 116,through the winding 61 of the rotary relay 59, winding 64 of thedi'erential relay 63 to the battery` tica The talking current energizesthe' ver-v relay` 58', wlnch'latter attracts its, ar-

matures T and vr108. The fornlerclosegv in contact with the point10S),-` and the latter (108),' closes in contact with "the `contactpoint 11 0. The talking current vin passing throiigh the windingv ($1 ofthe r tary relay in!) cncrgifzcs vsaid rclay, and tb" armature llsldrawn from -invcontactwith the -point .j M ...tlici'eby breaking theenergizing circuit extending from ground G* 'through the lamp @throughboth windings.y Suppose the subscriberfA.hasdehvered the niessageto theoperator-.and the operator has restored the substation-A and restorinAcerptfWt-iedoublenvound re ay 59.*wliich is maintained energized byrthe locking circuit l previously tra cedl-l In the meantime the sub-` fscriberfat 'A has not replaced the receiver n f on thesujitchhook, butdesires to add tothe vj in essagelD Accordingly the signalinglbutton A28 is; pressed,` grounding the vertical-'line conductor 79, which causesthe signal lainp f 'relayy (1G andto battirryjl.'l The armature .11,1.ei1ga'gi'es the pointv 112; which establishes f an energizing-circuit thro-ugh the winding "360; 'aid .cii'zcuit'locks the' relay 59in an op- "'eratcd position. until the said circuit is.Wbroknattheccijitact'point 113 and armature 1114.. Thislocking circuitextends from through battery B to ground G.. Since'both lings-. (l and05 of the relay G3 are difially, arranged,l the relayl armaturesand-'100 remain 4in vvtheir normal posi; lieven .though currentisp-flowing keyQEf-to norinalr position, as shown at E in Fig 2, thusremoving the talking circuit to D to laslry The circuits established in:bringing this about are as follows: from sub- '."stati'on, ground Gl,contact point'l, spring 28 s1`irings26 and 25, vertical line condu'c--toi-79, side-switch Wiper 42contact point 95,-sli`aftwiper 39, conductor115, through.- 1 the-Winding of relay 58, springs 7.4 and 751totheYbattery`lead84, thence through bat'- tery' B to rground G. Thevertical relay f '58' upon lenel'gizing ',attracts'the armatures y107a`nd108Which latter closes angl'energiz.- "ing,ci'icuitlthrough the lamprelay'havhich iiit'urn attracts its armature/ 103 andestabjlishesacircuit through the signal lamp 67, '-7.'asfpreviously traced.Theoperator iure- :spouse again" vthrowsvthe key E,`s\vitchingythesp1-1fngsYallotted'thereto as explained. he release of the signaling'apparatus- .1f when@the'keyv E is in normal positionis brought" aboutwhen'the subscriber A ressto'resjthe receiver 2 to thevswitch-hook 3andf` '1. simultaneiously` grounds both the vertical @an rotarylineconductors 79 and 80, re- ,spr-letively- `This 'results in a flow ofcurrent lays. This circuit Ve2; contact point 97, r through thewindingof the release relay 52.

the relays, eX-

.f `frein `substation ground G1 to the release-springs 32, 38 and 84,thenceover the conductor 79, through` the line relay 58,

springs y74 and 75 to battery? l5` and to ground G, as previouslytraced. The current flow over the rotary line extends from ksubstationground G? tothe release-springs 1 82 and'BB, rotary line conductor 80,thence through the relays 59 and 63, as previously followed, to'hatteryVB andto ground G, energizing the differential relay 88. energizationor'v the vertical relay 58 closes The in Contact .the armature 107 andthe contact pointr109, which places therelease relay' 52 "of therst-selector'in series' with the. re-

lease-ielay 62 of the signaling apparatus= `The current that passesthrough the 'Winding (il-of the' differential relay 63 magnetizes thecore, which' attracts thcarmature 102 and placesfincoutactthe'saidarmature and contact point 117,thereby establishing anenergizing circuit through the said release retends from ground Gt,switch Wiper 44,

switch-shaft Wiper 41 to the armature 107,

armature 114 to disengage froxnthe contact` r"point 113, thereby opening4the locking cir cuit through-the Winding @Cof .the rotary Irelay 5,9.The release relay 52 of the firstselector upon energization places in`contact "the springs 118 and 1.19,- which in turn comy lease magnet 51extending from ground G to the springs 118 and 119, release magnet 51 tothe battery lead 84C, thence through l11,1 y

itery B to ground G., f The release relaysan 'magnet 'thusl energized -fattract their respective armatures, and as soonfa's the su stationrelease springs 82,83 and ffsepaluf rate and break the. groundconnection With the line conductors 7 9 and 80thcy again deductor 79,release-springs 34, 33 and` 32 to fthe substation ground G1. ,SinceAthewinding "64 alone carries current the' .relay 63 be' comes active ad'clpses in'contact the armature -102 and Contactl point 117 andthevrenergize, releasing all apparatus brought [into service by the callingsubscriber. As- Ty sume that the calling subscriber A. replacesthe receiver before `the key'E is restored. Y "The release is thenbrought aboutl over slightly "different circuits. The differential ouslydescribed, the selector `-.atlalsecond attendants 551lieve the firstoperator;A likewise the .second iatte'fldant i may 4 transfer geo,

l #and contact p armature 106 and vertical relay 58 now becomesenergized by a. current flowing from the substation ground G1,'verticalline conductor 7 9 to the relay 58, springs 74 and 76, armature 106,contact point 120 to the battery lead 84, thence through battery B toground G. Thev armature 102 upon engaging the contact point '117completes the energizing circuit through the release. relays 52 and 62,and, as previ- C is released after the release-springs 32, 33 and 34Sepa- 1 rate;` the -connection to the circuit `D is y broken; the relay59 is denergized, and all energized parts are fully restored. `In asystem of great size Where the switches are divided into groups, fromevery ygroup there will lead off, of course, ten trunk lines to theboard in which all switch? ing circuits are located. The arrangementomaybe such that all the trunk lines termnate vat one operatorsposition, or if the traffic becomes heavy, additional operators lpositions may be provided, as shown in Fig. Y2.' `lVhen this arrangementis followed out it is sometimes desirable to transfer all the u calls toone operators position, for instance at night time. The work being slack'at night one operator may be able to take care of all the work, or twooperators, etc., Aas "is well known. Such an arrangement may beaccomplished ,with the provision of circuits vdisclosed in Fig. 2. Eachtrunk vline l v instead of being provided with only one key E may berovidedinaddition with mul- `tiple keys and H,'as indicated. -Each ofthe said keys F and H has a left-hand section which isfan exactduplicateofthe key E, and in addition a. Aright-hand section whereby the work maybe transferred from one' operatorfs position to the' next. 4Normallythekeys'F and H restin the position indicated 'a"t"H.-' If the keyisthrown in one direction the right-hand, set lof springs is.

switched'as shown at F, and if switched in the` reverse direction the",vleft-hand set of springs isv operated, y:is-,Shown at E, Fig. 1.

f the operatorat position"#1 (Fig. 2) wishes to 4 transfer all callscoming over the `triinkgline corc'l'uctors 115. and -116, the key theright-hand d as shown in Fig. signals will appear lamp and thus-re- 2whereby the incoming the `incoming 'signal's'fto a vthirdpp'erator, etc.`lnFig. 2 the key F is l shown operated .in suchA manner as to transferVthe'signal to the lamp 121 VVgization" plac'` s throughdthe signal lamp121.

'Said circuit l extends from ground. G

to the .springs 78 51 and 77 of ,thefkey E, springs 124 1125 contactpoint 120. The

latter Contact closes the circuit fthe rotary contact at position.#2.The` relay 66 upon 'ener-V in`-contact -the armature 103 int 1104,-which closes a circuit of the key H, springs 126 and. 127 of the key F,armature 103 contact springs 128 and 129 of the key I" .to the springs130 and 131 ofl the signal lamp 121 to thence through battery Theoperator in .136 disengages from the spring 137 and comes in contactwith the spring 138. This which supplies the calling substation withbattery current for talking purposes. The circuit extends from .ground Gthrough the winding of the differential relay 63, Contact point 105,relay armature 106, springs 138 and 136 and springs 139 and 140 of the4key H to the springs 141 and 142 of the key F, through the Winding ofthe vertical line relay 58, thence over the circuit as previ-' ouslytraced to the battery B and to ground G.. The talking lcurrent energizesthe vertical relay 58, which latter o perates with known results. Therelease of the signaling apparatus when the key H is in normal positionis .brought about when the subscriber A restores. the receiver 2 to theswitch-hook 3 and simultaneously grounds both the vertical and rotaryline conductors V79 and 80, respectively. This results in a flow ofcur-l rent from the substation ground (Si1 to the release-springs 32, 33and 34, thence over the conductor 79, through the line relay 58,vsprings 142 and 141 of the key F, sprin 's 'V140 and 139 and 136 and137 of the key il to the battery lead 84, thence to battery B and toground G. The current How over i line has already been'- traced.A Theenergization, of the vertical `relay 58 `closes in contact the armature107"and the relay 52 of the first-selector in series with the releaserelay 62 'of the signaling apparatus, With the result that thesaid'slgnaling apparatus and first-selector .are released' and fully(restored, as previously described. Thus it will be seen that When the.kevs E, F and H are in n'ormalposition all of the incoming calls overthe trunkconductors 115 and 116 are received by the first operator, andwhen the key-F is operated, as shown in Fig. 2, and the normal, theincoming calls are transferred from the first operators position to thesecondy operators position; likewise, when the key`.H is thrown,operating ther springs on the right, t he key F remains as shown,` andthen the incoming signals pass from i point 104,

the key H, through point 109, which places the release A keys H .and Eremain at if ya l ,4 J ,thefirst and second positions to thethirdk z L,operators position." Furthermore," itvwill be.`notic drtl1at thespringcombination'ofI ff, g, l'theleft side of'tliekeys F and H isexactly like thespring` combination -offkey E, 'The sprinL'sJGQ andf'()of theI key E, like the corl,responding springs 133 andlat, and-:3,143Landl'lltof the keys Hand F, respectively, t V areconnecteddirectly withthe conductors" i122 and123. ..The springs 68 andTl ofthe.

.keyvE-connect With thefoperators Setfg. also f f thesimilarsprings132'and 135 and '145' and 1146 .of'their respective' keysH` andr F con- "nectwith thev operators 'setfo-f their' respect `4 tiv'epositions.,r The'fspring 'Z5-.andthecor-- `responding springs 137 `and146oftl'1e 'keys A and F, respectivelyfarel connectedf'ivith theabattery-1'eadzS-.vv The'fspring 741` (1F-ig.` Al) i, =`fconnects-withtthe vertica1-1relay58';'butin v vFig. @fthe connection with the saidrelay is i i #from the spring "17 4 to the' springs 1447 v and,lflfwnwhen" th'ekey 'i'sjthrown and the krighthande-.set ofi "springsAis j operated, and-'to Springs i141 and`142'of thekeyF andtothevertical',relay` V58. .The corresponding'spring 136i fof'zthekey. 'Hconnects 'with thefsame f relay :through the slaringsf139=and140 'of i,1thekey-` H, springs 111 and 142 of key Flto l,the vertical lrelay 58.Also., the e'orrespond-A fspring'148offthey1iey F conneets'yvitht'hesaidrelay through VVthe-springs 149 and l11.42 l.Whenthe' key Fjisin' normalposition.v

-The spring' 76 and' the corresponding vsprings 138`aridj ,150, of thekeys-Hand F, respec y l 'l ""tively,areconnectedfwith.the armature-106,,1

'hundred andl ififtyohns each.

j .From-fh; fwgomgiit will beet-mehr 4am call `.o 1 signalis received,

. ':From theforegoing' 1t1 will beseen that. e

Aone oigniore operators"A or; attendantsidtele-- r `pl inescanbelocateflonone line', and; that" suc1i`line-is-in`the-,nature of ajtelephone line, iri'aslrnucl1,L as ity leads directly to af .tele-I 'L'phone'on'telephones In `such case r'neans are inoviled, as'E explained,for enabhng` a 'calling el|l)sci-iberk `\vho.-e1tclephone v'receivesilkingcurrent fromfthe exchange or central station'to `autornaticallyselectg the first idle one, of Said. telephone lines, If-these speciallinesfforjthefoperators or Vattendants then the other levelsl may bedevoted toregular' service-f that isvto. say,'they may have ordinarytrunk. lines'A leading thereffro'r'n'. For'the broader purposes of myin-1 vention, however, it' is not vnecessary thatv these spciall1nes`for the operators or at-v springs 126 and 12T, 124311117125, andA77v 'and-7 8 'produce additional breaks' in' the circuits` of "theoperators or attendants signaling lamps, so that thesejamps will be"jextinguishedby the operation of thel keys, y since' the 'signalfrelaly66de retained energizedveveri after fthefvoperator throws her key., Asshown, and for the more sp'ecic J purposesof vmy invention, theseAspecial televphone lines for' ythev operatorsor attendants are-:inthenature of one-'waylines-f-that isl to say,1theyare Vadaptedy for'calling only in one direction;y Y Inl other' words, they 'areadaptedo'nly frfthe ytransmission, of inn n'lead from a certainhlevelofthe first-selector,

coming calls, and' -not-.for the' transmission.

'of outgoing calls. ,In this way each oper#- ator r `or attendant" can.receive Acalls over thesev 'special lines, but cannottransmitl any,callsy -ov'e'rfthe sameiir the' oiplposite direction. When Aan operatororf'ffatt'endant ref ceives instructions, froma callingsubscriber,

long-,distance connection `canlfthen befma'de or trouble reported,laccording-to the duties.

' of the attendant receiving the message from theV calling subscriber.;Obviously, .all ,tenb

of the special telephone ,lines *0f course,-

' if@.`there should lbe tenpgreups 'offselectors the saine operator`cansuperintend the ten circuits 'froinneach-fof theften groups,l or

' contacts irrany certain `llevel--*say the tenthlv 1'eve1;of`a selectorcanfbe appropriated'foi'4 special 'servicein' callingI operators or atltendamtsat the 'exchange or central station,

so that each 'opratoncan 'supervise al1 ten y one vhundred circuitsi'nall. y, `rEvidently when.

rone hundred circuitsv are too .much for one. operator any number 'ofthem may betransfem-ed to another operator.V asexplamed. If

'desired ythese special telephone'y lines could be'extended to an therstation "r eicliang'ei` to ena-ble a calliligwsubscribefr of Aoneexchangeto directly `call an loperatorA or nttendant :at the 'o her--exchangri GbVOUSlY ductor being used for 2i-leasing purposes, as

man-v 'other ilsesfrr-,y my in\ention "will sag gest themselves to!those-skilled 1nlv the 'artjr'v' A' in addition to. thosefwhich 'I have-inenl Nforysupplying-operating' current from the yWell-as for inclusionin the energizing circuit v'of therelay which controls the line lampsignals associated with the operators telephones. During conversation itwill be seen that, the common battery or centralized source of operatingand talking current is kbridged across the special service vline orcircuit through the medium of relay-coils associated with said specialservice line or circuit.` 'In this Way current for talking purposes issupplied over the special service line or circuit to the callingsubscribers line;

` .'What I claim as my invention is l. In a telephone `exchange system,the combination of a line, a plurality of operi ators` or attendantstelephones on said line, a visual signal for each telephone, a callingsubscribers line, automatic means for con-A necting the calling linewith the other said J line, parallel circuits for said visual signals,relay means controllingsaid circuits, means by which one operator orattendant may direct the incoming calls to the visual signal of the nextoperator, and means for supplying talkingcurrent over a portion of saidfirst lineto the calling subscribers line. "2., In atelephone exchangesystem, the combination of a line, a pluralityy of operators orattendants telephones on said line, Va*call-receiving device for eachtelephone, calling subscribers line, automatic means for connecting thecalling line with the said other line, means by which one operator mayi5 disconnect fromV the line and direct all incoming calls to the nextoperator, and means for supplying talking current over a portion ofvsaid first line to the calling subscribers line. ,40, In a telephoneexchange system, the combination of a calling subscribers line, aspecial service line, a telephone `on said special service line, a callsignal for said telephone, trunk lines for regular service, automaticmeans for connecting the calling line with thefspecial service line, andmeans for supplying talking current over a` portion of the specialservice line-to the calling subscribers line. A i i 4'. In a telephoneexchange system, Athe combination of a calling subscribers line,trunklines for regular service, apluralityv ofwspecial service lines,telephones on said '5 special service lines, an automatic selector- ),5,switch adaptedtoestablish connection with y the first idle one of saidspecial service lines, orwith the rst idle trunkline when used l ltorregular service, a centralized source of talking and4v operatingcurrent, connections,

. said source to the s aid selector-switch, and -means` for bridging thesaidsource across the automatically .selected specialv service line tosupply talking current to 'the 4 calling 65. subscribersvline.

said third relay,

.cuit for said second relay,

5. In a telephone 'exchange system, the combination of a callingsubscribers line, a special service line, automatic means for connectingthe calling line with the special service line, a telephone on saidspecial service line, a visual signal associated With said telephone, alistening-key for connecting the telephone With'the special serviceline, a circuit for said visual signal, a relay for controllingr saidcircuit, an energizing circuit for said relay, a second'relay forcontrolling said energizing circuit, and a local locking circuit forsaid second relay.

6. In a telephone exchange system, the combination of a callingsubscribers line, a special service line, automatic means for connectingthe calling line with the special service line, a telephone on saidspecial servvice linea visual signal associated With said telephone, alistening-,key for connecting the telephone with the special serviceline, acircuit for -said visual signal, a relay for controlling saidcircuit, an energizing circuit for said relay, a second relay forcontrolling Said energizing circuit, a local locking circuit for said`second relay, a third relay controlling 'said local circuit. anenergizing circuit for vsaid third relay, and two additional relayscontrolling'the circuit of Said locking circuit being also controlled bythe second relay itself.

7. In a telephone exchange system, thel combination of a callingsubscribers line, a special service line, automatic means -for' fconnecting the calling line with the special 100 service line, atelephone on said special servlice line, a visual signal associatedwithsaid telephone, a listening-key for connecting the telephone with thespecial service line, a circuit for said visual signal, a relay for con-10F trolling said circuit, an energizing circuit for said relay, asecond relay fpr controlling said energizing circuit, a local lockingcira thirdrelay controlling said lo'al circuit. an energizing cir- 110cuit for said third relay, and two additional relays 4controlling thecircuit of said third relay, said locking Ycircuit being also con- 1trolled by the secbnd relayitselfgthe said first-mentioned relay havinganother euere' 115 gizing circuit controlled by the two additionalrelays.

8. A telephone exchange system provided 'with aline, an opera-tors orattendants telephone onsaid line, a visual signal associated with saidtelephone, suitable meansbywhich a calling subscriber may makeconnection with said line, a circuit for' said visual signal, a relaycontrolling said circuit, two energizing circuits -for said relay, k

a relay controlling one energizing circuit,` and another relaycontrolling the other cnergizingcircuit.'

"9. A telephone exchange system provided with a line, an operators orattendantsghtelel12(7) krsignal when the 'selector establishes connelion with a special 'serifice line, alealling sul. "seriheifs line '0 jhe selector, said' selector providec K Itoumtihiiieans"foi-causingiiirto sto Y or ooiiie -i'i-si, on tlieuil-rsifidle trunk linel'orfoiithe aqcordingi "to the phoneon said line, a yvisual 'eallsignalassolcialed with said telephone, a key-switch forConnectingftlie'*telephone with the line, suitl l abley means by uliih acalling subscriber Connectshiiiiseli vwith said line fandcau'ses lliedisplayof said signal, means for restor- :aing lsaid signal upon the actuation of ysaid ing'a displayof saidlsignal when thevoperaf*toi're'stores the lcey' L noi'iijial]il'iositio'ii. p y

Y10;4 In telephone exchange system, an

opeiators for attendaiits telephone;` a' visual signal 'associated withsaid vrteleliihoiie, mea ns forj'operating said signal-to eause'adisplay thereof,y a key-switeli proif'ided avith means for retiring'said signal, 'ivlieii the'telephone`v l; is brought into use,`and'grelay means forl fpreifenting ay display of said signal `when theA-ltey-suitcli .is ifestoredlo rnormal'-po'si,n

y .711'. loa telephone "exchange system,l the vtor {telephones-'onsaidlirstfment'ioiied line,

- a eiillfsi'giial uassociated with each telephone,

y y eomlgiin'atiouLof aralliiigz, subscribe s line, a i special .serviceline, a subserihei"sy individual fswitch, for automatically establishingconf` nectioii 1Wlitli K sa idy line `V trunks for* regular fswitoliv atelelihone ou said special' service,

linegfa all-signal 'associated with said`teley.coinhiiiatioiyofsi'unkflines for. regular sorva liankoi" irontatsorlerlniiifals1inil'lof said lmestermmate, telephones on said*r specialservize lines7` eall-,signalsasililefl'l" ivitlll iid telephones,Vlautoii'iatir means fonca lisini;r the opeiiatioijiyf a' call-* fj ii lle sicial rservizlie line, rter of tliejoall."

means by which one operator kmay direct the i y inroiiiinggautouiaticcalls tothe next oper:kn ,",jtoi'gaiul uien-nis for supplyingtalkingreur- 1 rentoi'eifaportion of said first line fto the callingsiilisCi-ibes line.'

service also leading from saidindividual@ ,A combination of a`cf'illing'y subsribeisline, 'a

centralized soureeof V`talking current for said subscribers line, ayoneiway special service line a'claptedfor'calling only in fone'dilrection, ywhich. special service 'line 'lisnoty 70.`

available forservicebetween other lines, a

telephone' onsaid special service lineya call-r signal associated,W-th'said telephone7 sub- Y somber-controlledautomatieineaiis b `whichconnection` sestablishedbeliweenft e sul "f7` y scribers line andfthespecial service line, airtomaticm'eans for causiiigftlie operation `ofsaid signalwhen connection lis made .with` 1 the* specialy seivicejline,an yimpulse-trans yphone.,` and n ueai'isincludingv al relay' for au-,jv aidsigp 4 nal iyhen the; individual switch 'establishes liorliridgngitlie said ysourcevavross vtli'e aufwitli saidj line,

mittinff mechanism fforftphe callingv line, adaptgd to `control saicl`means for connecting `with the truiilg ,andahook-switchfonthea-llingline butfseparate from said. inleclian'ism.v -v i f 15,. In a:telephone exchange. systfeiii,A 'the combination of' a plurality foflilies,r 1 telephones'- fr `said flin'es; K operators? keyj switchesfoi-*connecting said telephonesv with said flinesya Visual signalassoeialsed with 90 each y vtelephone relays" controlling each.' sig-y.tomatically placingftli'efcalling line in conf' lines nieanscoiitrolledbyfone' of said relays for automatical* Yoperatiiiggf they visualIsignal of one of said'f telephones wlienjf-such a' yConnection isestablished," 'nfieans` controlled y' by anotlieroi said relays forrendering saidr signal i inoperative, -rand :means foisupplying talkin'gcurrent {drei-"thecalled line .to .theasuhsorihei"s telephone., j j .16,In a'telepline exoh'angesysliem,the'f `(-,oii-iliinati'oii offa'iallingVsulisri befrs line, vtrunk lines lfor. regular vser-vice;,af 'plurality`ofv 'special service A"l ines, telephones onf said specialservieeilinesganf aulmuia'tioselecto switch adaptegl'toy es ablishconnectionwith v anyidle one of- -said'sl ecial"service lines,v or.ivith an idle trunk-linefwlienu ed'forregu-'- laiwseryice, acentralized! soul-begofalking source to `-,the said selector-switoh,and'riieaus Q; supply .talking oui-rent toftlie. milling' sul- Lscrihersline. H 'l f 7. ylnfa telephone exchange system, theromlii nation offa.'li neu having);Y ,af third @mp v 12av iblishin-g1:connection l frelease 'iiiecliani'sm` ,-gfor.. .said

duotor. a telephoneonfpsaid line, automatic switvliin'g means ,iorx

fautoinatio -siviteliiiig gni'eans, -a -releasezircuit i nclu'ding ysaid rthird oo riduotor,'Y` and :means '418. "ln a telephone/exchangie'` sys-teimfthe v y combination of"aflinehaving a ythird con-uln l s Y. y dutor,atelephoneongsaid line, lautomatic' lnfafrtelehoneeichanie sistem the ,s y PY .Y

50 v telephones on said special service lines, callallotted to said lineand controlling nor' lmally open switch points in said circuit.

' said telephone with said other line,

means including an operators listening-key ton'iaticuieans for causingthe operation of.

with said line, release mechanism for said f automatic switching means,a release circuit including said third conductor, and relays 19. In atelephone exchange system, the combination ofa line having threeconductors, automatiemeans for establishing connection withv said line,release mechanism for said automatic means, a release circuit includingthe third conductor of the line, a

telephone allotted to said line, means for connecting the vtelephonewith the two main conductors of said line, l and relay means allotted tosaid line and controlling the said release circuit. i

420. In a telephone exchange system, the coinbinationof trunk lines forregular service, a plurality of specialservice-lines or circuits, acalling subscribers line, automatic means by which the callingsubscriberselects an idle special service line or circuit,.

or an idle trunk line, release mechanism for said autoniaticnieans,means allotted to said special servicelines or circuits and adapted forcontrolling said release mechanism, tele-V phones onsaid special servicelines or circuits, a signal for each telephone, and a common battery o rcentralized source of current for furnishing current to the callingsubscribers line for talking and signaling purposes. l

21. In a'telephone exchangev system, the combination of a callingsubscribers line,

vanother line, a telephonepav common battery,

automatic means for establishing connection from the calling line to thesaid otherline,l operators switching means for connecting 1 said havingprovisions for establishing the flow of talking current tothe callingsubscribers line when the operator listens-in.

22. In a telephone exchange system, the

combination of trunk lines vfor regular ser# vice, a plurality ofspecial service lines, which lines are-not available for service betweenother lines, an automatic selectorswitch having a bank of contacts ortermihals in which allof said linesterminate,

signals associated withsaid telephones, au-

a call-signal when the lselector establishes connection with a specialservice line, a calling subscribers line, means for enabling thecallingr subscriber to start the operation of tlieselector, saidselector provided with automatic means for causing it to stop or come torest on an idletri/ink line, or oii anlidle special service line,according to the character-of the call.

. 23. In a telephone system, a line having;

a third conductor, a bridge on said line, a

'switch for making connection to saidline,

responsive to the calling subscriber,means in said bridge responsive tothe calling ysubscriber forvreleasin'g said switch over thetliirdconductor, and a ltelephone Vfor saidlin'e.

2l.. In

bridge on said line, means for extendinga call'to said line, a telephonefor said line,

means for supplying talking current over sai-d bridge and line in thedirection of the calling subscriber, a signal atc the telephone,

and means controlled by the relay of said bridge res onsive to thecalling subscriber for contro ling said signal.

25. In a' telephone exchange system, thecombination of a line having athird conductor, a telephone on said line, a signal for said linecontrolled over said third conduc' 26. In a telephone exchange system,the

a release circuit including said third v 7o a telephone system, a line,a relay Awith said first line, release mechanism for circuit includingsaid third conductor, land means allotted to said first line and adaptedfor controlling said release circuit', said-last i means controlled oversaid calling line.

said*- automatic switching meansfa release 27. In a telephone system, aline having y a third conductor,.a signal for saidline controlledover'said third conductor, a bridge on said line, a switch for makingconnection with said li-ne responsive to the calling s ub-y scriber,means in said bridge responsive to the calling subscriber for releasingsaid switch over said third conductor, and a telephone for said line.

Signed by me at Chicago,l Cook county, Illinois, this 218th day ofSeptember, 1906.

BERNARD D. WILLIS.

-Witnesses:.

Eowmi'n D. FALEs,' ARTHUR B. Sunni.

